The present invention relates to water injection systems for adding controlled amounts of water to the fuel supply of an internal combustion engine, and more specifically to a water injection system wherein the supply or flow rate is controlled as a function of exhaust manifold pressure.
The benefits of injecting controlled amounts of water into the cylinders of an internal combustion engine together with the fuel have long been recognized. Tractors, racing cars and aircraft, as well as passenger automobiles, have employed various systems for injecting water into the fuel intake primarily as a means of increasing the power output of the engine. Water injection may also have other benefits, such as increasing gas mileage, reducing knocking or pinging due to pre-ignition, reducing engine operating temperature, and promoting cleaner fuel burning to lessen deposits of carbon and other foreign matter in the engine and exhaust system.
Prior art systems for injecting water into the engine fuel intake include complex and expensive as well as relatively simple systems. For example, some water injection systems utilize tachometer inputs, water pumps, electrical controls, and the like for metering the flow of water into the fuel intake system. Others rely upon variations in the sub-atmospheric pressure (or vacuum) within the fuel intake manifold to pull in the water from a supply container. Although the latter are more economical, they do not always provide the optimum amount of water required by the engine for added power and knock suppressant.
It is a principal object of the present invention to provide a system for injecting a controlled amount of water into the fuel intake of an internal combustion engine which is simple and economical in construction and operation, yet automatically controls the flow of water in an optimum manner.
Another object is to provide a water injection system of novel and improved construction wherein the amount of water added to the fuel intake of an internal combustion engine is automatically regulated in accordance with the requirements for added engine power and knock suppressant under any given driving conditions.
A further object is to provide a water injection system which is easy to install on the internal combustion engines of existing vehicles for improvement of a number of operating characteristics thereof in an optimum manner consistent with the requirement therefore.
Other objects will in part be obvious and will in part appear hereinafter.